Water goes from liquid to solid, freezes Instantly!
Oh, I only got into rime icing while flying once and it was during on of my typical January birth month check rides and I wowed my check pilot. I could get into the details but it would bore you but some times you have to climb UP out of it and then do a fast approach through it to be safe. And you have to do it BEFORE the aircraft gets really iced up as the aircraft not only can gain a lot of weight but it will disturb the lifting ability of the wings (or rotor blades).
Colgan Air Flight 3407 disaster was a rime ice accident but if the pilots realized what was happening and climbed above it while they still had enough power, the accident may not have happened. Sad, very sad.